A house burns at the Cocos fire in nearby San Marcos. Fire agencies throughout the state are scrambling to prepare for what is expected to be a dangerous year of wildfires in this third year of extreme drought.

Fire engulfs a structure Thursday in Escondido, Calif. One of the nine wildfires burning in San Diego County suddenly flared Thursday afternoon and burned close to homes, triggering thousands of new evacuation orders.

A house burns at the Cocos fire in San Marcos, Calif., Thursday. Fire agencies are girding for what is already proving to be a dangerous year of wildfires, as California suffers an extreme drought.

David McNew
/ Getty Images

Originally published on May 16, 2014 8:56 pm

This post was updated at 8:45 p.m. ET

A 57-year-old man was charged with arson in one of 10 wildfires that have swept through San Diego County this week, burning more than 30 square miles and causing millions of dollars in damage.

The Associated Press reports that Alberto Serrato pleaded not guilty on Friday to arson in a 105-acre fire in suburban Oceanside that started Wednesday. A spokeswoman for the San Diego County district attorney's office said witnesses claim to have seen Serrato adding brush to the flames, but did not see him starting the fire.

Meanwhile, some evacuated residents were returning home, while others have no homes to return to, reports Brooke Binkowski of member station KPBS.

Some evacuation orders in other areas have been lifted as firefighters gain control, aided by easing weather conditions. But some residents are returning to find their homes burned-out shells.

The first death with a potential connection to the fires was reported by KPBS Thursday, after firefighters found a badly burned body in a transient camp in Carlsbad, where the 400-acre Poinsettia Fire has destroyed 18 apartments and either destroyed or badly damaged eight houses.

"Nearly 16,000 new evacuation orders were issued in San Marcos and nearby Escondido Thursday," CBS News reports. "Over the last four days, officials have told 125,000 people to leave their homes. More than 2,500 firefighters are working across San Diego County aided by water-dropping aircraft."

Hundreds of people are in shelters, and residents who are trying to go about their lives are forced to navigate around the fires, which have caused many roads and highways to close.

As San Diego County copes with the fires, police arrested two teenagers last night for suspected arson. Police say the pair "started at least two brush fires in San Diego's Escondido area," NBC 7 News reports. Investigators have not tied the pair to any other fires in the area.

Three large and still mostly uncontained fires have now burned more than 17,000 acres in the area as of Friday morning (local time), according to member station KPCC's Fire Tracker. Another blaze, the Bernardo Fire, is 75 percent contained after burning more than 1,500 acres, officials say.

The 6,000-acre Tomahawk Fire "has grown past the containment line and is approaching the city of Fallbrook," KPBS reported Thursday.

From San Diego, Tom Fudge of KPBS tells our Newscast unit:

"San Diego old-timers say they've never seen such hot, dry winds in May. But those winds have been blowing for three days, and so far, 25 homes have been lost.

"Today, the most serious of several fires has been threatening the northern San Diego suburb of San Marcos. Cal Fire commander Tom Porter points out California's drought has left a very dry landscape — 'to the point where we have dead vegetation and fuels that are very volatile.'

"This weekend, the Santa Ana winds are expected to diminish and disappear."

Before that promised relief arrives, San Diego will endure another day of high temperatures. The National Weather Service forecast calls for highs in the 90s for much of the county Friday.

Related:

For more on fire conditions in California and across most of the U.S., check out NPR's Fire Forecast app, which is updated daily. The interactive should take you right to San Diego County, but you can change the location by entering a new "ZIP code, city, etc."